It really doesn’t matter. Just go and remember your friend.
I don’t have a black suit, last couple of family funerals i’ve been to neither did most people – even amongst the octogenarians – trousers and a jacket seemed the concensus.
Once went to my great aunts ‘no black funeral.’ Me in chinos and a green tie, dad & brother in similar; mum in pink, gran in orange. They’d changed the no black and never informed us! Every other person was in full black. Stood out a bit! Too add fully brand this memory in the mind, it was the first time i’d been to a burial, the rain was biblical and the service was in hebrew.